Boundaries
by AnimateObsessive
Summary: Set in an alternate universe in which Sasuke died when Sarada was young. Just before his death, Sasuke made Kakashi promise to take care of Sakura and Sarada. Kakashi has kept his promise by becoming a substitute husband/father figure. But Sakura seems to want more from him than he was originally willing to give... Note: Mainly KakaSaku, but prevalent SasuSaku as well. Oneshot.
A/N: I refer to Boruto as "Bolt" in this. I honestly prefer that name. This is completely AU anyway.

" _Take care of them, Kakashi-san. I'm trusting you to keep them safe."_

Kakashi awakened with Sasuke's words in his ears. He had been dreaming about him once again, his mind arranging the features into various states of aging. He never seemed to be a full-grown man in the dreams. He was always a boy, a teenager, a male perched on the very edge of manhood. But never exactly as he'd been that day. It was all the same in Kakashi's mind. His former students never aged. Time simply rebuilt their lives and their faces to give the illusion of growing up.

And what had time done to him? Changed him, naturally, but also thrust him into a life he'd never imagined for himself. Every day, Kakashi awakened to what he at first assumed to be a life that had lost most of its direction. Then, as the veil of sleep was fully lifted, he would realize that it was merely the remnants of another dream tugging at his emotions. Whether he liked it or not, there were responsibilities, there was a direction, and there were promises. Recalling these things, Kakashi would hastily rouse himself.

 _Why me?_ he often wondered. _Why not Naruto?_

Because Naruto had a family. A wife, children, and a new position that dominated the portion of his life unoccupied by either. To forcefully liberate him from these things would have been an act of cruelty. But Kakashi had none of these things. His freedom was decidedly dreary, but it was a freedom nonetheless.

A certain incident soon after Sasuke's funeral ultimately decided things for Kakashi. He would remember the incident vividly for his entire life, for it was the first time such emotions had been stirred within him. He had come over to Sakura's home in order to speak to her about Sasuke's words and about the promise he'd made. At the time, Sakura and Sasuke's daughter Sarada was only three years of age. Kakashi and Sakura settled on the couch in the living room to talk, whilst Sarada was playing in the yard.

"Is...is it really okay that he asked something like that of you?" Sakura demanded, a slight tremble in her voice.

Only a few days had passed. Her voice still shook at the mention of her deceased husband.

Kakashi chuckled grimly.

"Don't you want to honor Sasuke's wishes, even if you don't believe in me?" he replied bluntly.

Sakura's cheeks reddened. When Sasuke had spoken those words on his death bed, she'd paid little attention to them. As she lay weeping over his body, she'd only thought about her sorrow and what was to become of her life. It was only after the funeral had passed that she thought about her husband's last words and their meaning. She was happy that he'd been thinking of her safety moments before he died, but a sense of bemusement lingered.

"That's...that's not at all….!" Sakura began indignantly, but choked on the lie.

The sudden distress in her mother's voice caught Sarada's attention as she entered the room. She was holding a bouquet of freshly-picked yellow flowers. She frowned, her eyes wandering from her mother to the man that set beside her. She did not know this man very well, although she'd seen him once or twice. He seemed to be comforting her mother, his hand placed gently on her shoulder. Smiling, Sarada strode to the couch and tugged on the leg of Kakashi's pants. When he turned his attention to her, he noticed that there were grass and dirt stains all over her face and arms. He reached down to pat her head, as he'd once done to Naruto, but Sarada took hold of his hand. With a cheerful giggle, Sarada gently pressed one of the flowers into Kakashi's open palm.

Kakashi's heart melted. He was caught in the innocence of Sarada's smile, the love for her mother that showed plainly in her eyes. His reluctance disintegrated. At all costs, he wanted to protect that smile.

Sakura slid a cup of coffee over to Kakashi's side of the table. It was early in the morning and she hadn't gotten much sleep, but she had still managed to go through her morning routine with little disturbance. Truth be told, Kakashi's smiling face was a welcome sight in her current state. She returned his smile as she settled into the seat across from him with her own cup of coffee.

"You're here early," she commented. "I can't tell if this is a miracle or if you're drunk."

Kakashi secretly thought it was a miracle that Sakura wasn't snapping at him, as she usually did in the mornings. Or at least she seemed to do this on the rare occasions he was actually at her home in the mornings. Yet this morning she was acting relatively pleasant, although she'd again forgotten that his coffee mug was likely to remain untouched.

"I appreciate the confidence," Kakashi responded sardonically.

Sakura took a long sip from her mug, enjoying the poignant bitterness and heat. When she lowered her mug, there was a slight questioning look on her features.

"Those boys that were bothering Sarada a few days ago…," she began slowly.

Kakashi's expression was impassive.

"They suddenly stopped bothering her for some reason," Sakura informed him. "I like to think she stood up to them and they decided to leave her alone, but…..I'm not entirely sure about that."

Kakashi arched his eyebrow, as if he was surprised by these facts.

"Oh?" he replied innocently.

Sakura eyed him with an amused expression.

"Did you happen to speak to them?" she demanded, a slight grin on her face.

Kakashi crossed his arms defiantly, but turned his head away from the woman's rather accusing stare.

"I only gave them a friendly warning," he told her.

Sakura laughed. She'd known all along, from the moment Sarada casually mentioned that "those stupid bullies" had abruptly decided to leave her alone.

"A friendly warning?" Sakura echoed teasingly. "Did your "friendly warning" make them run away in terror?"

 _More like slink away in terror, the little bastards,_ Kakashi thought in satisfaction.

Those foolish bullies had briefly stood up to him, challenging his demand for them to leave Sarada alone. Kakashi had enjoyed putting them in their place.

"Then I'll have to teach you a lesson," he'd replied in a dangerously calm tone. "And I really hate teaching lessons….."

He'd leaned forward, locking eyes with the tallest, meanest-looking boy in the group.

"…..so if I have to do it, it's not going to be very pleasant," he finished.

Then he'd watched as all four of the boys fled like cowards, their rebellious bravery suddenly forgotten. Judging by the looks on their faces, he had a feeling they wouldn't be bothering Sarada again.

"Was that necessary?" Sakura asked, although she was smiling.

The word "necessary" hadn't crossed Kakashi's mind. He wasn't certain if his actions fell under that category, but that was of little consequence to his contentment. Additionally, the fact that Sakura was smiling reassured him. She wasn't angry at him. If anything, she was impressed.

"Well, you would have done the same thing," Kakashi answered.

Sakura laughed again.

"You're too sweet," she told him. "Sarada is fortunate you exist."

She stared at her reflection in the coffee. She could see the distinct marks of age on her face. Taking care of a child had taken its toll on her, but she thought she still looked much the same as she had when she was younger. She still wore her hair short and her eyes were still a soft shade of green. Sitting across the table from her former sensei, she could have been discussing their latest mission. She could have been a teenager with a crush again, instead of a woman with a ten-year-old daughter, a dead husband, and a man trying to fit into the gap said husband had left. Returning her gaze to Kakashi, Sakura realized that, with the curtains drawn in the kitchen, she could almost ignore the fact that he too had aged.

" _I'm_ fortunate you exist," she added. "If you weren't here, I don't know what I would have done."

Kakashi was surprised. Sakura had always clearly been grateful for his help, but she'd never expressed it in words. She'd showed her thanks by cooking for him on occasion, by frequently smiling at him, by being generally amiable towards him. Kakashi couldn't ask for anything more from her. He was merely doing this because he cared about her and because he'd made a promise.

"Sarada likes you, too," Sakura continued. "She talks about you as if you're...you're..."

She stopped, the grip on her mug tightening. She bit her lip, the words she'd been about to say hanging in the air. The uncomfortable silence was almost tangible.

"Ka-Kakashi-san, the two of us….," she finally stammered, a soft passion in her voice.

Her hands were beginning to redden from the heat of her coffee mug. She was gripping it even tighter now, tight enough for it to hurt. She was looking into Kakashi's eyes, but in a way that suggested she wasn't actually looking at him. She was staring through him, her vision focused on a Kakashi from the past, a younger Kakashi she had admired as a sensei. A Kakashi who had pledged to deliver her from her burdens and protect her.

The house was empty, except for the two of them. Sarada had left with Bolt twenty minutes ago. In the absence of a third person, the silence around Kakashi and Sakura seemed to thicken. It was as if they were both waiting for Sarada to enter the kitchen and distract them. But of course this did not happen, and the quiet steadily became too much.

Sakura reached across the table and seized Kakashi's hand. She squeezed it gently, blushing as she gazed into Kakashi's eyes. She was no longer looking through him.

"Kakashi-san, would you please...sleep with me tonight?" she inquired serenely.

Last night, Kakashi had been forced to stay over at the house due to a storm. It was the first time he truly spent the night at Sakura's home, although he slept on the couch. In the middle of the night, Sakura had gone into the kitchen seeking a cup of something warm to help her sleep. She'd passed Kakashi's sleeping form and felt a peculiar warmth in her body. She'd paused to regard the slumbering man, her cheeks burning. Briefly, she'd been fascinated by the presence of his sleeping form, of the warmth his body had undoubtedly been giving off. She'd leaned over him for a moment, suddenly compelled to touch her lips to his. But she'd hastily recoiled, abruptly coming back to her senses. Yet that feeling that had come over her had never entirely left her. That pressing desire for Kakashi's warmth followed her into the kitchen, back through the living room, and into her bedroom. She couldn't forget her thoughts, those perverted wonderings, that had gone through her head in that instant.

Kakashi looked at his hand in Sakura's grip. She was holding it close to her chest. He imagined, although it was fairly impossible, that he could feel her heartbeat. A strong, rapid thumping beneath her blouse.

"I'm not going to sleep with you," he replied candidly. "Get that thought out of your head immediately."

Sakura leaned closer across the table, threatening to upset her coffee. She didn't care. She wanted to be closer to him, in the hopes he would get a better look at the expression on her face.

"You want to, don't you?" she uttered in a knowing, quiet voice. "I see the way you look at me sometimes. When you don't think I'm paying attention, your attitude changes."

Kakashi tried to pull his hand from Sakura's grip. He was surprised when she released him easily.

"You're imagining it," he told her sternly.

This was possible. She could have been misreading the signs and only seeing what she wanted to see. But she hadn't imagined the way she felt the other night. The raw, animalistic emotions that had risen in her chest when she looked at Kakashi's sleeping form were beyond fantasy.

"Am I?" Sakura replied in a teasing manner.

Kakashi looked towards the door, hoping in vain that a distraction of some kind would appear. But no one arrived to save him from this conversation. Eventually, after an entire minute of waiting, he gave up.

"You can't just hop into bed with me because its been a while," Kakashi pointed out with a sigh.

He was right to a degree. Sakura and Sasuke had only slept together once during their marriage, prior to Sasuke leaving the village. This event was how Sarada Uchiha had been conceived. It had also been the night Sakura lost her virginity. Since then, her life had been devoid of sexual gratification. And in truth, she hadn't been particularly anxious for it. But the previous night had awakened something inside of her, something buried and lost.

"I'm not asking because I'm desperate," Sakura responded evenly. "If I was desperate, I would ask for more."

She took Kakashi's hand in hers again, closing her eyes as she squeezed it.

"Sarada is staying over at a friend's house tonight," she informed Kakashi pointedly. "I'll be all alone. I want you to come over and sleep with me."

Sakura opened her eyes and saw that Kakashi's expression had changed. He no longer appeared slightly exasperated. He was regarding her as if he was finally taking her request seriously.

Kakashi reached forward and gently removed Sakura's hands from around his. He noted the slight objection as he did so, as if this time she was more determined to hold on. Despite the relative heat of the room, her hands were cold.

"I can't do that," Kakashi told her firmly. "It wouldn't be right."

He was thinking of Sasuke. Kakashi remembered the way their eyes had met during his last moments.

"Because of Sasuke?" Sakura surmised, a knowing tenderness in her voice.

It had taken years, but she'd managed to shed the miserable tremble that had once accompanied Sasuke's name. She found she could think of him without sobbing or falling to her knees in despair. Time had washed away all but the deep-rooted emotions, leaving her to her daily routine. And as she looked across the table at Kakashi, it occurred to her that he might be one of the reasons she was able to finally let go. He had managed to play the part of the doting husband that, admittedly, Sasuke had never been. His devotion to the role had cleansed her of various regrets. Smiling, Sakura idly ran her finger across the edge of her cup.

"It was all thanks to you," she uttered softly. "I was able to let go of Sasuke's death and look toward the future because you filled that hole in my life. As much as I loved Sasuke-kun….I can't imagine him doing the things you did. I can't picture him as the attentive, doting husband and father you became."

The words "husband" and "father" struck Kakashi directly in the heart. He'd never expected to hear either term applied to him. After reaching a certain age, he'd dropped such prospects. He readied himself to be the old, retired sensei who occasionally had lunch with one of his former students and was treated to a surprise birthday celebration every year. But he had fallen directly into the two roles he'd ceased to consider plausible.

"I'm not going to ask you to marry me," Sakura continued matter-of-factly. "I only want you to sleep with me."

 _Boundaries._ The word flashed into Kakashi's mind, restraining any descending thoughts with its presence. He knew about _boundaries_. He'd always been careful with Sakura. He'd never attempted to hold her hand when they went shopping for food or playfully kissed the back of her neck. He'd never hugged her or made any remark that might come off as flirtatious. He made sure that most of their conversations began and ended on terms befitting _friends._ But somewhere along the line, the term _boundaries_ seemed to have gotten tangled in the illusion.

"Are you going to keep asking until I give in?" Kakashi demanded.

Sakura lifted her coffee to her lips, returning Kakashi's slightly annoyed expression with a smirk.

" _Will_ you give in?" she retorted. "I'm asking for you to do me a favor. I want you to take my mind off of it all, for just one night. It's not an unfair request, is it?"

 _It's unfair to_ me, Kakashi thought bitterly.

Their coffee had lost most of its heat. Sakura grimaced as she poured the remainder of the barely-warm drink down her throat. When she was finished, she stood up and strode to the sink with her empty cup. Her back to Kakashi, she turned on the water.

"I want you to take my mind off of it all," Sakura repeated calmly.

Kakashi didn't reply. He sat at the table motionless, frowning at his reflection in his own untouched cup of coffee.

In the end, they slept together. It wasn't spectacular, nor was it terrible. Looking back, Sakura would recall it as being mechanical. They were merely animals, machines even, going about their designated tasks. The first machine held, and then steadily entered, the second machine. The second machine made all the appropriate noises and gave all the expected reactions. Everything the first machine did, the second reacted to it blankly, robotically, almost tearfully. And when it was finished, both machines made forgetting a priority.

Sakura's lust was satisfied, but she wasn't happy. She felt as if she'd violated something, something that no one should ever violate. In the darkness behind her eyelids, she saw Sasuke. She saw them becoming one in their bedroom. If she focused on the memory long enough, she could almost feel the tears and the sweat as their bodies moved in unison. For one brief second, as Kakashi penetrated her, she almost believed it was Sasuke.

 _Sasuke-kun…,_ Sakura thought dismally as she lay in bed.

It wasn't guilt she was feeling. It was a sense of loss, as if a memory had been taken from her.

Kakashi was the guilty one. His regrets weighed on him heavily the next morning. He looked at himself in the mirror, his mind swimming with miserable thoughts. He hadn't simply overstepped his boundaries with Sakura. He had _destroyed_ them, crushing the barriers and tearing the remains to shreds with his teeth. He'd trespassed in Sasuke's private domain, otherwise known as Sakura's womanhood. The regret was unrelenting.

A week passed. Two weeks, then three, then four, then five, sped past. Sakura continued with her daily routine. Kakashi provided aid in any way he could, relieving Sakura from the stress of raising Sarada and keeping the house in order by herself. He fell back into the role of the faux husband/father as if he'd never left it. Normality returned. For those five weeks, a forced silence prevailed.

Then the five weeks concluded. Normality melted away as all the emotions that had spawned on that night rushed into Sakura's mind. It occurred abruptly, as if a switch had been flipped. She was dusting at the time, a smile on her lips. She was content, her mind on her work and nothing else. Then her duster lightly tapped a picture of Sasuke and Naruto on her bedside table. In that instant, every other emotion in her mind and body vanished. She dropped the feather duster, her hands quivering violently as waves of remorse washed over her.

Kakashi found her three minutes later. She was on her knees, the picture pressed against her chest. Her eyes were closed. Kakashi approached her cautiously, as if worried she might begin sobbing.

Sakura detected Kakashi's presence in the room without turning around, but she did not move from her position.

"You left," Sakura whispered. "You left and when you came back….you were dying. I couldn't save your life. Even with all of my knowledge, all of my hard work….I couldn't save the life of the man I loved. I'm as useless as you said I was…."

She clutched the picture tighter against her chest.

Kakashi did something he'd warned himself against. Something their boundaries did not allow. But there weren't any boundaries anymore, he realized dourly. There was only a scarecrow and a cherry blossom, thrown into a life neither of them had asked for but both of them accepted.

Sakura only gave the slightest reaction as Kakashi embraced her. She was numb to his warmth. The only thing she felt was the picture she was holding so close to her heart.

"I failed," Sakura continued, her voice heavy with sorrow.

All these years, Kakashi had interpreted Sakura's remorse as merely the consequence of losing someone she loved. But that was only the most obvious part of it. As he held her in his embrace, he realized that he could understand how she felt. That haunting feeling of having caused misfortune, of having others fall to one's own inadequacy. Kakashi was finally seeing the cold reality of Sakura's inner torment.

"You didn't fail," Kakashi assured her, his own voice quiet and soothing. "You did all you could."

Sakura shook her head in firm objection.

"I couldn't…," she began.

But Kakashi tightened his grip, as if attempting to extract the misery from her by force. He could hear the impending tears in her voice.

"No," he uttered, his tone pleading. "Please, don't do this to yourself. _Don't."_

Sakura loosened her grip on the picture. She tilted it back to reveal the smiling face of Naruto, his immense grin contrasting Sasuke's bitter scowl. It was the only picture she had of Sasuke showcasing him as a full-grown adult. The sight of it made her heart swell with nostalgia.

Sarada appeared in the doorway of the bedroom, a worried look on her face.

"M-Mom?" she stammered. "Are you...alright? You didn't answer when I called…."

Kakashi had nearly forgotten about Sarada's existence. In his rush to comfort Sakura, it had slipped his mind that Sarada would be arriving home shortly. He turned to the girl and offered her a reassuring smile that did not quite reach his eyes.

"Are you hungry?" he asked. "I could make you something if..."

Suddenly, Sakura broke free of Kakashi's grip. She got to her feet unsteadily, as if she'd momentarily forgotten how to walk. She swayed in place for a second, her slightly dazed eyes locked on her daughter. She stepped forward with the uncertainty of an intoxicated person. When she was close enough, Sakura reached forward and seized her daughter, wrapping her in a tight hug.

"Mom!" Sarada yelled in protest.

But Sakura didn't let go. The tears she had been holding back were finally flowing.

Sakura waved to Sarada from the doorway, grinning at her leaving daughter.

"Be nice to Bolt, okay?" she called. "He's been having a bad week!"

Sarada rolled her eyes. Her mother was always encouraging her to at least attempt to get along with Bolt, but she found him insufferable. She much preferred Kakashi's point of view: A little rivalry was good for youth. However, she smiled and returned the wave.

Kakashi appeared next to Sakura in the doorway just as Sarada turned around. Sakura idly leaned her head on his shoulder, staring at the back of Sarada's head with a frown.

"Do you think she'll get into a fight with Bolt... _again?"_ she asked worriedly.

Kakashi chuckled. Some things simply refused to change, even as time marched forward.

"Yes, she will," he replied. "She tries her hardest to get under his skin and he always takes the bait. They're perfectly balanced."

He shook his head, amused.

"I can't wait until she's sixteen and they finally start dating," he commented.

Chaperoned, if Kakashi had anything to do with it. Preferably by someone willing to use excessive force if Bolt dared try anything. And only after Kakashi had a long man-to-man talk with Bolt about what he was and was not allowed to do, under penalty of imminent death.

"You're quite romantic," Sakura uttered, laughing.

The two of them returned to the house, Sakura closing the door behind them.

Kakashi wrapped his arms around Sakura, embracing her from behind. He planted a tender kiss on the back of her neck, causing her to giggle.

"Sarada is staying over at a friend's house again," he reminded her. "Do you want to sleep together again tonight?"

Sakura appeared slightly annoyed at the question.

"Did you stay over last night just so you could ask me that first thing in the morning?" she demanded.

Kakashi shook his head, his expression turning grim.

"That's not it," he answered. "I stayed over because Sarada told me she found you sobbing over that picture again."

Sakura's smile disappeared. She hadn't even realized Sarada had discovered her in such a state. She'd assumed that the footsteps in the hallway and the feeling of not being alone at the time were only her distressed imagination. She bit her lip, realizing how terrible the scene must have appeared to poor Sarada.

Kakashi released Sakura, smiling reassuringly even though she wasn't facing him.

"We don't have to sleep together," he told her. "I could just spend the night again."

Sakura opened her mouth to inform him that she preferred the first idea, but stopped. It had been weeks since the last time she slept with Kakashi and the last had been the third time overall.

"I'd….really like that," she replied instead.

It was possible that Kakashi had crossed all of his boundaries. But somehow, the idea did not faze him in the slightest.


End file.
